Prevalence and characteristics of pain in patients with lower-extremity ulcers-A cross-sectional study

The study aimed to investigate the prevalence and characteristics of pain in different ulcer types and to identify factors associated with pain experience in patients with lower-extremity ulcers. A cross-sectional single-centre study was performed, including 130 newly referred outpatients with lower-extremity ulcers. Pain intensity was measured with a visual analog scale (VAS) and pain characteristics with the short form mcgill pain questionnaire-2 (SF-MPQ-2). The mean pain intensity was 29.5 (SD 31.8) at rest and 35.5 (SD 34.1) during movement (0-100 VAS). 61.5% of the patients experienced pain (VAS > 0) at rest and 70.8% during movement. Moderate to severe pain at rest was seen in 39.2% and in 43.8% of patients during movement. The mean total score on SF-MPQ-2 (range 0-220) was 35.9 (SD 32.6). Most of the patients described pain as intermittent (mean 11.8 SD 13.9). Analgesics were prescribed for 78% of the patients. Ulcer type (i.e., arterial, immunological, pressure and venous) and age were associated with pain severity, and women had a significantly lower well-being score than men. Prevalence of pain in patients with lower-extremity ulcers was high across different ulcer aetiologies. Pain intensity and quality must be assessed to obtain adequate pain management.

Temporal and differential proteomic profile of molecular mediators associated with chronic and acute wound healing

The underlying pathophysiology of nonhealing chronic wounds is poorly understood due to the changes occurring at the gene level and the complexity arising in their proteomic profile. Here, we elucidated the temporal and differential profile of the normal and diabetic wound-healing mediators along with their interactions and associated pathways. Skin tissues corresponding to normal and diabetic wounds were isolated at Days 0, 3, 6, and 9 representing different healing phases. Temporal gene expression was analyzed by quantitative real-time PCR. Concurrently, differential protein patterns in the wound tissues were identified by Nano LC-ESI-TOF mass spectrometry and later confirmed by Western blot analysis. Gene ontology annotation, protein-protein interaction, and protein pathway analysis were performed using DAVID, PANTHER, and STRING bioinformatics resources. Uniquely identified proteins (complement C3, amyloid beta precursor protein, and cytoplasmic linker associated protein 2) in the diabetic wound tissue implied that these proteins are involved in the pathogenesis of diabetic wound. They exhibit enhanced catalytic activity, trigger pathways linked with inflammation, and negatively regulate wound healing. However, in the normal wound tissue, axin 1, chondroitin sulfate proteoglycan 4, and sphingosine-1-phosphate receptor were identified, which are involved in proliferation, angiogenesis, and remodeling. Our findings demonstrate the correlation between elevated gene expression of tumor necrosis factor-α, interleukin (IL)-1β, and identified mediators: aryl hydrocarbon receptor nuclear translocator, 5'-aminolevulinate synthase 2, and CXC-family, that inflicted an inflammatory response by activating downstream MAPK, JAK-STAT, and NF-κB pathways. Similarly, in normal wound tissue, the upregulated IL-4 and hepatocyte growth factor levels in conjunction with the identified proteins, serine/threonine-protein kinase mTOR and peroxisome proliferator-activated receptor gamma, played a significant role in the cellular response to platelet-derived growth factor stimulus, dermal epithelialization, and cell proliferation, processes associated with the repair mechanism. Furthermore, Western blot analysis indicated elevated levels of inflammatory markers and reduced levels of proliferative and angiogenic factors in the diabetic wound.

Adipose-derived stromal cells for nonhealing wounds: Emerging opportunities and challenges

Wound healing complications affect thousands of people each year, thus constituting a profound economic and medical burden. Chronic wounds are a highly complex problem that usually affects elderly patients as well as patients with comorbidities such as diabetes, cancer (surgery, radiotherapy/chemotherapy) or autoimmune diseases. Currently available methods of their treatment are not fully effective, so new solutions are constantly being sought. Cell-based therapies seem to have great potential for use in stimulating wound healing. In recent years, much effort has been focused on characterizing of adipose-derived mesenchymal stromal cells (AD-MSCs) and evaluating their clinical use in regenerative medicine and other medical fields. These cells are easily obtained in large amounts from adipose tissue and show a high proregenerative potential, mainly through paracrine activities. In this review, the process of healing acute and nonhealing (chronic) wounds is detailed, with a special attention paid to the wounds of patients with diabetes and cancer. In addition, the methods and technical aspects of AD-MSCs isolation, culture and transplantation in chronic wounds are described, and the characteristics, genetic stability and role of AD-MSCs in wound healing are also summarized. The biological properties of AD-MSCs isolated from subcutaneous and visceral adipose tissue are compared. Additionally, methods to increase their therapeutic potential as well as factors that may affect their biological functions are summarized. Finally, their therapeutic potential in the treatment of diabetic and oncological wounds is also discussed.

Current In Vitro Biofilm-Infected Chronic Wound Models for Developing New Treatment Possibilities

Significance: The prevalence of chronic wounds is increasing worldwide. The most recent estimates suggest that up to 2% of the population in the industrialized countries is affected. Recent Advances: During the past few decades, bacterial biofilms have been elucidated as one of the primary reasons why chronic wounds fail to heal. Critical Issues: There is a lack of direct causation and evidence of the role that biofilms play in persistent wounds, which complicates research on new treatment options, since it is still unknown which factors dominate. For this reason, several different in vitro wound models that mimic the biofilm infections observed in chronic wounds and other chronic infections have been created. These different models are, among other purposes, used to test a variety of wound care products. However, chronic wounds are highly complex, and several different factors must be taken into consideration along with the infection, including physiochemical and human-supplemented factors. Furthermore, the limitations of using in vitro models, such as the lack of a responsive immune system should always be given due consideration. Future Directions: Present understandings of all the elements and interactions that take place within chronic wounds are incomplete. As our insight of in vivo chronic wounds continues to expand, so too must the in vitro models used to mimic these infections evolve and adapt to new knowledge.

Evaluation of the wound healing activity of the crude extract of root bark of Brucea antidysentrica, the leaves of Dodonaea angustifolia and Rhamnus prinoides in mice

BACKGROUND

Wounds are major problems of developing countries that can be managed alternatively using traditional medicinal plants. Since majority of currently available drugs for wound management are expensive and pose problems such as allergy and drug resistance, it is pivotal for the world to have intensified inquiries on the claimed medicinal plants to come up with wound healing chemicals being affordable, effective and safe. Ethiopian traditional healers recruit a wide range of medicinal plants with wound healing activities. Root bark juice of Brucea antidysentrica, the leaves of Rhamnus prinoides and Dodonaea angustifolia are claimed among others in the folklore medicine. Therefore, the aim of this study was to evaluate the in vivo wound healing activities of the root bark juice of Brucea antidysentrica, the leaves of Rhamnus prinoides and Dodonaea angustifolia in mice.

METHOD

The root bark juice of Brucea antidysentrica, the leaves of Rhamnus prinoides and Dodonaea angustifolia were collected, dried, ground to coarse powders. Then the crude extract was obtained by macerating with 80% methanol. The filtrate was dried, reconstituted in appropriate solvent and the wound healing activity was evaluated using excision and incision wound models.

RESULTS

On the last day of treatment, 80% methanol extracts from the selected medicinal plants showed a significant wound healing activity against control as supported by an increase in % wound contraction and a decrease in Epithelialization period. Ten percent of Rhamnus prinoides showed significant wound contraction against the control (P < 0.05) on days 2 and 4. But on day 6; except 5% extracts of Brucea antidysentrica and Rhamnus prinoides; all doses of extracts contracted the wound significantly (P < 0.05). Extracts of Dodonea angustifolia (5% & 10%) and 10% of Rhamnus prinoides and Brucea antidysentrica increases wound contraction rate with increasing significant level on days 8 & 10 (P < 0.01) and 12 &14 (P < 0.001). Among the extracts, 10% of Dodonea angustifolia showed maximum percent (99.9%; P < 0.001) of wound contraction followed by 5% Dodonea angustifolia (99.15%; P < 0.001) and 10% Rhamnus prinoides (99.00%; P < 0.001) on the last day of treatment. In addition; significantly shorter healing time was attained by 5% &10% leaves of Dodonea angustifolia (P < 0.01), 10% leaves Rhamnus prinoides & root barks Brucea antidysentrica (P < 0.05). Ten percent of Rhamnus prinoides & Brucea antidysentrica (P < 0.05) and both doses (5% & 10%) of Dodonea angustifolia (P < 0.01) significantly increased the tensile strength by 54.10%, 56.58%, 63.04%, and 79.19%, respectively against the control.

CONCLUSION

The 80% methanol crude extracts of the study plants support the traditional claims for healing of wounds as evidenced by an increase in wound contraction rate and tensile strength, decrease in Epithelialization period.

Development of a Peptide Derived from Platelet-Derived Growth Factor (PDGF-BB) into a Potential Drug Candidate for the Treatment of Wounds

Objective: This study evaluated the use of novel peptides derived from platelet-derived growth factor (PDGF-BB) as potential wound healing stimulants. One of the compounds (named PDGF2) was subjected for further research after cytotoxicity and proliferation assays on human skin cells. Further investigation included evaluation of: migration and chemotaxis of skin cells, immunological and allergic safety, the transcriptional analyses of adipose-derived stem cells (ASCs) and dermal fibroblasts stimulated with PDGF2, and the use of dorsal skin wound injury model to evaluate the effect of wound healing in mice. Approach: Colorimetric lactate dehydrogenase and tetrazolium assays were used to evaluate the cytotoxicity and the effect on proliferation. PDGF2 effect on migration and chemotaxis was also checked. Immunological safety and allergic potential were evaluated with a lymphocyte activation and basophil activation test. Transcriptional profiles of ASCs and primary fibroblasts were assessed after stimulation with PDGF2. Eight-week-old BALB/c female mice were used for dorsal skin wound injury model. Results: PDGF2 showed low cytotoxicity, pro-proliferative effects on human skin cells, high immunological safety, and accelerated wound healing in mouse model. Furthermore, transcriptomic analysis of ASCs and fibroblasts revealed the activation of processes involved in wound healing and indicated its safety. Innovation: A novel peptide derived from PDGF-BB was proved to be safe drug candidate in wound healing. We also present a multifaceted in vitro model for the initial screening of new compounds that may be potentially useful in wound healing stimulation. Conclusion: The results show that peptide derived from PDGF-BB is a promising drug candidate for wound treatment.

Insights into Host-Pathogen Interactions in Biofilm-Infected Wounds Reveal Possibilities for New Treatment Strategies

Normal wound healing occurs in three phases-the inflammatory, the proliferative, and the remodeling phase. Chronic wounds are, for unknown reasons, arrested in the inflammatory phase. Bacterial biofilms may cause chronicity by arresting healing in the inflammatory state by mechanisms not fully understood. Pseudomonas aeruginosa, a common wound pathogen with remarkable abilities in avoiding host defense and developing microbial resistance by biofilm formation, is detrimental to wound healing in clinical studies. The host response towards P. aeruginosa biofilm-infection in chronic wounds and impact on wound healing is discussed and compared to our own results in a chronic murine wound model. The impact of P. aeruginosa biofilms can be described by determining alterations in the inflammatory response, growth factor profile, and count of leukocytes in blood. P. aeruginosa biofilms are capable of reducing the host response to the infection, despite a continuously sustained inflammatory reaction and resulting local tissue damage. A recent observation of in vivo synergism between immunomodulatory and antimicrobial S100A8/A9 and ciprofloxacin suggests its possible future therapeutic potential.

Mature B cells accelerate wound healing after acute and chronic diabetic skin lesions

Chronic wounds affect 12-15% of patients with diabetes and are associated with a drastic decrease in their quality of life. Here, we demonstrate that purified mature naive B220⁺ /CD19⁺ /IgM⁺ /IgD⁺ B cells improve healing of acute and diabetic murine wounds after a single topical application. B cell treatment significantly accelerated acute wound closure by 2-3 days in wild-type mice and 5-6 days in obese diabetic mice. The treatment led to full closure in 43% of chronic diabetic wounds, as compared to only 5% in saline-treated controls. Applying equivalent numbers of T cells or disrupted B cells failed to reproduce these effects, indicating that live B cells mediated pro-healing responses. Topically applied B cell treatment was associated with significantly reduced scar size, increased collagen deposition and maturation, enhanced angiogenesis, and increased nerve growth into and under the healing wound. β-III tubulin+ nerve endings in scars of wounds treated acutely with B cells showed increased relative expression of growth-associated protein 43. The improved healing associated with B cell treatment was supported by significantly increased fibroblast proliferation and decreased apoptosis in the wound bed and edges, altered kinetics of neutrophil infiltration, as well as an increase in TGF-β and a significant reduction in MMP2 expression in wound granulation tissue. Our findings indicate that the timeline and efficacy of wound healing can be experimentally manipulated through the direct application of mature, naive B cells, which effectively modify the balance of mature immune cell populations within the wound microenvironment and accelerate the healing process.

Immune Modulating Topical S100A8/A9 Inhibits Growth of Pseudomonas aeruginosa and Mitigates Biofilm Infection in Chronic Wounds

Pseudomonas aeruginosa biofilm maintains and perturbs local host defense, hindering timely wound healing. Previously, we showed that P. aeruginosa suppressed S100A8/A9 of the murine innate host defense. We assessed the potential antimicrobial effect of S100A8/A9 on biofilm-infected wounds in a murine model and P. aeruginosa growth in vitro. Seventy-six mice, inflicted with a full-thickness burn wound were challenged subcutaneously (s.c.) by 10⁶ colony-forming units (CFUs) of P. aeruginosa biofilm. Mice were subsequently randomized into two treatment groups, one group receiving recombinant murine S100A8/A9 and a group of vehicle controls (phosphate-buffered saline, PBS) all treated with s.c. injections daily for up to five days. Wounds were analyzed for quantitative bacteriology and contents of key inflammatory markers. Count of blood polymorphonuclear leukocytes was included. S100A8/A9-treatment ameliorated wound infection, as evaluated by quantitative bacteriology (p ≤ 0.05). In vitro, growth of P. aeruginosa was inhibited dose-dependently by S100A8/A9 in concentrations from 5 to 40 μg/mL, as determined by optical density-measurement (OD-measurement) and quantitative bacteriology. Treatment slightly augmented key inflammatory cytokine Tumor Necrosis Factor-α (TNF-α), but dampened interferon-γ (IFN-γ) levels and blood polymorphonuclear count. In conclusion, topical S100A8/A9 displays remarkable novel immune stimulatory and anti-infective properties in vivo and in vitro. Importantly, treatment by S100A8/A9 provides local infection control. Implications for a role as adjunctive treatment in healing of chronic biofilm-infected wounds are discussed.

Excretions/secretions from medicinal larvae (Lucilia sericata) inhibit complement activation by two mechanisms

Larvae of the blowfly Lucilia sericata facilitate wound healing by removing dead tissue and biofilms from non-healing and necrotic wounds. Another beneficial action of larvae and their excretions/secretions (ES) is down-regulation of excessive inflammation. As prolonged complement activation is key to excessive inflammation, the aim of this study was to elucidate the mechanisms underlying the anti-complement activities of ES. Results revealed that heat sensitive serine proteases in ES degrade multiple complement proteins in all steps of the three complement activation pathways. Importantly, C3a and C5a-major activators of inflammation-were also degraded by ES and pretreatment of these factors with ES completely blocked their ability to induce activation of human neutrophils. Pre-exposure of the neutrophils to ES did not affect their responsiveness to C3a/C5a and fMLP, indicating that the receptors for these activators on neutrophils were not affected by ES. Surprisingly, heat and serine protease inhibitor pretreatment did not affect the ability of ES to inhibit C5b-9 complex formation despite degrading complement proteins, indicating a second complement-inhibiting molecule in ES. Heated ES was as effective as intact ES in inhibiting C3 deposition upon activation of the alternative pathway, but was significantly less effective in wells with a classical or lectin pathway-specific coating. Unfortunately, the molecules affecting the complement system could not be identified due to an insufficient database for L. sericata. Together, larval ES inhibit complement activation by two different mechanisms and down-regulate the C3a/C5a-mediated neutrophil activation. This attenuates the inflammatory process, which may facilitate wound healing.

Assessment of circular wound healing in rats after exposure to 808-nm laser pulses during specific healing phases

BACKGROUND AND OBJECTIVES

Low-level laser therapy (LLLT), is an important application modality for the advancement of wound healing processes. In this study, histological and morphometric analyses have been made to understand and compare effects of high-power 808-nm pulses on circular skin wounds among groups irradiated immediately after wounding and groups irradiated at specific stages of the healing period.

STUDY DESIGN

Experimental groups were as follows: Laser Therapy (LT) was received as three sessions of laser irradiation (6.38 J/cm2, 1.276 W/cm2, 808 nm) immediately after wounding (Inflammatory group, n = 12), 24 hours post-wounding (Proliferative group, n = 12), and 72 hours post-wounding (Remodeling group, n = 12); the Control group (n = 12) received no irradiation. Histological analyses were performed on the 3rd, 7th, and 14th days post-wounding.

RESULTS

Mean wound diameters were 5 mm for all groups. On Day 7, wound diameters were measured as 2.99 ± 0.17, 2.95 ± 0.3, 2.52 ± 0.11, and 2.41 ± 0.34 mm for the Control, Inflammatory, Proliferative, and Remodeling groups, respectively. At 2 weeks post-wounding, dermal tissue in the Inflammatory and Proliferative groups closed superficially, while 1.30 ± 0.1 mm and 1.30 ± 0.06 mm openings remained in the Control and Remodeling groups, respectively. Mean wound healing rates (WHR) for all treatment groups were found to differ significantly from the control group (P < 0.05). Upon comparing the Proliferative group with the other treatment groups, a significant difference was found. However, no significant difference was found between the Inflammatory and Remodeling groups, with the former having a slightly higher mean value.

CONCLUSION

Histological and morphometric results showed that high-power, low-energy application has the best effect when first applied 24 hours post-wounding (late inflammatory, early proliferative stage) as demonstrated by increases in granulation tissue, fibroblasts and collagen deposition, which lead to faster rates of wound contraction and thus accelerated healing.

Synthesis and Evaluation of Biological Activity of Antimicrobial--Pro-Proliferative Peptide Conjugates

Skin represents the largest organ of the human body and plays a crucial role in its protection from the negative impact of the outside environment, maintains its homeostasis, enables sensory interaction and thermoregulation. The traumatized skin tissue undergoes several phenotype switches due to progressive reoxygenation and release of cytokine and growth factors, that activate mechanisms of reparative processes. However, in case of wounds colonized with pathogenic microflora natural regenerative mechanisms become substantially impaired, that could lead to chronic inflammatory states with non-healing skin lesions. Herein, we present the initial results of our studies aimed at the design of bifunctional peptide-based compounds. The chemical approach, that was utilized in this work, was based on the conjugation of antimicrobial peptides with the peptides, that have potential pro-proliferative and/or cytoprotective activity towards human keratinocytes and fibroblasts, in order to obtain antimicrobials with reduced cytotoxicity or compounds that maintain both activities, i.e. inhibit bacterial or fungi growth and activate cell proliferation/migration in in vitro tests. As a result, we obtained a group of peptide conjugates that effectively inhibited the growth of selected bacterial and fungi strains and were able to stimulate proliferation and migration of keratinocytes and fibroblasts under their effective microbicidal concentrations.

“Toothbrush” the Feet

Chronic wounds develop when the sequence of healing events are disrupted, usually in patients with underlying diseases such as diabetes mellitus, venous insufficiency, peripheral artery disease, and neuropathies and they affect most often the lower extremities. We present a 68-year-old woman with plantar ulceration, lasting for approximately 18 months, resistant to healing with conventional therapy and various modalities we used. The patient had a long history of seronegative enteropathic arthritis, Crohn’s disease, secondary fibrillar amyloidosis, multiplex neuropathy, and small vessel vasculitis, the latter being the trigger event for the ulceration of her right foot. Before the decision for a final surgical intervention, we implemented a mechanical periodic stimulus using a soft toothbrush, which resulted in the gradual and complete healing of the ulcer within a period of 6 weeks. Patient’s history and previous treatments are presented along with the procedures that led to the healing of the chronic wound. This report supports the idea that periodic mechanical stimulus is of great importance for the healing process and this could be the mechanism of action of some other methods that have been described in the medical literature.